The Act of Love by Howard Jacobson

Do not read this if you want your heart to remain untroubled. I admit that when I was sent this in hardback, I found it unfinishable: it was so powerful that I felt that it would finish me, instead of the other way round. (Do not read this if you are anywhere near the precipice of love: it is that unbalancing.)

Its essential plot could be written on the inside flap of a matchbook in fairly large handwriting. I shall pad it out. Felix Quinn, an antiquarian bookseller, is devoted to his wife, Marisa, whom he has stolen from a previous husband. Felix, though (his surname may be Quinn, but it might as well be Culpa), believes that no man can be said to truly love a woman until he has imagined her in the arms of someone else. The idea is expressed, sometimes in somewhat ruder language, more than once throughout the novel, for it is an idea that many people are reluctant to take on board.

The key word, though, is "imagined". This is what gives the book its power, depth, and indeed its very existence. Felix brings together his wife and a younger man, a solipsistic intellectual called Marius. He encourages them to have an affair; he could be said to have willed it into being, as a novelist wills the work into being.

This area of the erotic has been addressed by Jacobson since at least his second novel, Peeping Tom, but here his fiction is stripped of the usual Jacobson accoutrements (Jewishness, Manchester, you know the drill). Its action takes place all inside Felix's head, and I choose my words carefully. It is, in fact, more of a meditation, an essay on a certain kind of love, as well as on love itself. "Until we are in love - my sort of love - we pass one another by. We take glancing notice when our interest is aroused, we half perceive or carelessly wonder, but we do not truly observe or interrogate until we love. This is how we know love from its poor relations: by the greed with which we devour its object ... Only artists are as voracious in their gaze and curiosity."

As for Felix, the narrator, I could not even begin to describe him, beyond the details that he is not ugly and has a similar kind of mouth to his grandfather (who appears, in a marvellous little cameo, with James Joyce, which I will not spoil for you here). This is quite deliberate; he is a blank, a conduit for thoughts, a chamber for experiment. The three main characters are themselves improbable. An antiquarian bookseller who lives in a grand, multi-chambered house in Marylebone? A woman as desirable as Marisa? (You too, reader, will burn for her, even if you are a woman. Jacobson has taken some care about that.) A serial seducer of women who is not only called Marius - as was Walter Pater's fictional Epicurean, so a name which carries its own resonances - but has, rather like Pater in fact, walrus-like moustaches?

But Marylebone itself is thoroughly plausibly described. This is a great novel of place; I took particular pleasure from checking that Thomas Couture's Roman Feast is just where Jacobson says it is in the Wallace Collection, and that, yes, you can just about hide behind its frame a folded piece of A4 notepaper with an assignation on it without any of the gallery's guards asking you what you're up to.

So, this is a game ("words deceive", we are warned here, and this is a great deception; Felix's surname could also be Krull); and yet it is not a game. In fact, its artificiality makes it all the more penetrating, all the more likely to insinuate itself under your skin. You cannot even soothe yourself by saying "it's only a story", as you can with most disturbing narratives. It is more than that. This falls into the category of novels which, because they have seemingly thought themselves into existence, are their own creation, so to speak, and threaten to pop like a bubble (or, like Marvell's metaphysical dewdrop, are their own tear); they carry a greater charge in their own insubstantiality than anything more solidly conventional. It is an almost frighteningly brilliant achievement. Why did the Booker judges not recognise it? Scaredy-cats.